'Captain' is a rank,
Do you mean as in military rank such as Captain (Army) or Captain (Navy ) and is it the captain of a ship? Or the Seaman in Command or even the commander?
All very confusing. I was flying in command of the old Lincoln bomber when I was 21 but never called myself "Captain" lest I be laughed out of the Sergeants Mess as a poseur. There was a first pilot and second pilot and I was the first pilot. Sometimes called "Skipper".
Nowadays go to any flying school and witness the proliferation of gold stripes on 200 hour flying instructors calling themselves "Captain" because they fly as pilot in command on a Cessna. It is all a big wank, really.
